Dead Kiwi 2 ?

My new Kiwi 2 is reading an S5 but receiving no signals at all. Power cycling it did nothing. Thoughts ?


Comments

  • jksjks
    edited April 4

    Bob, I finally got around to testing that BB Green you returned to me that you were sure caused S9 noise across the entire spectrum when you used it.

    It's as quiet as a mouse. Absolutely the same as dozens of other BBG's I have here.

    So unfortunately I think you must have a serious local noise issue there. It doesn't necessarily have to be with your own equipment (power supplies etc). It could be the neighbor's crappy solar panel installation or something.

    Each Kiwi-2 is carefully tested for no-antenna conditions and with the new self-test function. There is simply no way a problem like this would have gotten past our test guy.

  • Bob's posting may be kind of ambiguous. For me it seems to describe a different (new) problem rather than the recent "S9 noise across the entire spectrum, possibly caused by the BBG itself". It sounds more like a "deaf" kiwi than a "no antenna condition".

  • That's wild.....after I got the new BeagleBone working at a normal noise floor, I took the 'noisy' one and put it back together. Even with no antenna connected, it was showing S9 noise and radiating that noise out of the antenna port. It was repeatable here. That remains a mystery but I am out in the country and have a very low noise floor.

    This is a new problem and it is with the new Kiwi2. I have another one that was running for a few hours and eventually a few minutes and then not at all. This one has a defective fan so Isuspect heat eventually took it's toll. BTW, where can I get a replacement fan for that ? So I took the reliable Beaglebone from the Kiwi2 and paired it with the one that wouldn't stay visible for long. Thankfully, the pair performed fine for my upcoming solar eclipse Monday. So now I have a Kiwi2 board that gets no signal on any frequency (and shows an S5) even with an 800' longwire as an antenna and a Beaglebone that won't show on my.kiwisdr.com. As the spectrum display shows, the noise floor goes up at the low end. Again, no difference with or without an antenna attached. When I opened the Kiwi2, I noticed it has no fan. The room is always 80 degrees F. Is there any chance the lack of a working fan in the Kiwi1 and the lack of a fan in the 2 been a factor ? Heat seems likely a factor in the failed fan 1 but I know nothing about how the 2 is cooled. I have a good sized external fan on the one I made work today. Need guidance :)

  • It's not clear to me if you have you got one good working KiWi, and if that KiWi is made up of a collection of parts from the KiWi 1 & 2.

    It seems to me like there are a number of problems here, and each one needs to be individually identified.

    Mixing and matching parts just confuses the issue, as it adds even more variables.

    You seem to have a high noise floor, even with no antenna connected. So I think as a starting point, I'd have a look at the power supply you are using.

    The next problem is that you don't see any signals when an antenna is connected. Can you verify with another receiver that the antenna is working ? Are the connectors you are using faulty ?

    Have you tried using the internal signal generator to determine if you can see any signal at all ?

    Could you have inadvertently damaged the KiWi in some way during installation ?

    Have you tried reflashing the KiWi with a clean SD card image ?

    Regards,

    Martin

  • Hi Martin,

    I appreciate the reply as always and apologize for muddying the waters with too much information.

    The biggest issue is the new KIWI2 stopped receiving signals and was showing about an S5 noise floor. It and another Kiwi1 were fed from the same antenna via a splitter. The other Kiwi1 works fine. I swapped the splitter outputs and the 1 still works and the 2 doesn't. I was unaware of an internal signal generator. How do I access it ?

    I have not tried re-flashing the Kiwi....I assume that is not via the BeagleBone or is there a way to re-flash the Kiwi2 as well ?

    All 3 of my Kiwi's are fed from a single 3 amp low noise power supply. The 2 that are working both show an S1 or less noise with no antenna so I am assuming that the power supply is not suspect. I did try a separate power supply and got the same result.

    The Kiwi2 was installed when I got it a couple months ago and worked perfectly until it abruptly stopped. No trace of any signal on any frequency.

    Bob

  • The signal generator is one of the KiWi extensions.

    It generates an internal test signal, so it doesn't validate everything, but at least it will tell you if the software is working correctly.

    The easiest way to reflash your KiWi, would be to make a backup SD card with your good KiWi, using the backup facility in the admin menu.

    Then use that SD card to reflash the problematic KiWi. Turn the faulty KiWi off, then insert the card and repower it. Once the KiWi has stopped running again, remove the card and repower it. It will be a cloned copy of the original KiWi, so make sure the original KiWI is offline whilst you do this.

    If the faulty KiWi is now working again, change the IP address and port number in the admin menu, so that it doesn't clash with the original KiWi. Then the original KiWi can be repowered and everything should be OK.

    If you read through the KiWi setup guide, or use the search function on this forum, you should be able to find additional guidance.

    Regards,

    Martin

  • Hi Martin,

    I got it to register on my.kiwisdr.com for a minute or two but no more. I tried to reflash it but under no circumstances could I get any of the 4 LED's or the ones near them to flash. I was not looking at the LED's when it briefly worked. This is the one that needed more and more reboots until it got to this point. The fan had failed at some point so I suspect heat may have cooked it.

    Bob

  • OK,

    Does the KiWi V2 board work when plugged into the Beagle board of a working V1 ?

    Regards,

    Martin

  • Unknown but a V1 Kiwi is running fine on a V2 Beagle board now. Have a couple of Green Beagles on the way...should arrive toward end of week.

  • edited April 12

    Hi Martin,

    The Beagle Green arrived and making the copy from the other Kiwi was easy. The Kiwi 2 shows sig gen shows -100 on the meter as it should. Nice low noise. Switching back gives 30db more noise floor. The antenna that produces -30 on a working Kiwi shows -90 here. 1010 khz is the strongest AM signal and it is just above the noise. It can be observed at 207.135.223.250:8095

    Bob


  • That doesn't look good, unless I misunderstood your comment.

    If the internal signal generator seems to produce a signal of around the correct level, I suspect the RF input connector, attenuator or RF amplifier stage has somehow got damaged.

    What happens when you adjust the attenuator setting, can you see any change in signal level or noise floor with the antenna connected ?

    Regards,

    Martin

  • Good Morning Martin,

    The RF attenuator does make a difference. When set to -30, the local AM signal that is just above the noise at S7 drops to S6 and is no longer audible. -30 seems to reduce the carrier by closer to -10db. The noise floor is around -110db unless I put the signal generator on and then it drops to -170. Not sure if it is normal for the many other carriers to show on the spectrum when using sig gen or not. It was working fine with another Kiwi fed from the same splitter....the other one is fine.


    Bob

  • The attenuator should reduce any off-air signals by the amount of attenuation shown on the slider control.

    If setting it to -30dB, only results in a slight drop in signal level, from S7 to S6 (which equates to 6dB) then it looks like the attenuator chip could be fried.

    Just an educated guess on my part, but it does look as if something had been physically damaged.

    Regards,

    Martin

  • Thanks for your assessment Martin....I'll wait to hear from John as to what the repair options might be.

    Bob

  • I can't follow this conversation. Too much missing and conflicting information. And I'm drowning in other more important problems.

    This is what you must do before we even talk about sending it back: Take the short SMA-M to SMA-M cable that came with the Kiwi-2 and connect it between the EXT CLK and RF IN connectors on the Kiwi-2. Make sure they are snugly hand-tightened.

    Send Kiwi Internet access link and admin password to support@kiwisdr.com

    Thank you

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